Sorry, I meant to say Master database, not system. It was requested that it be on C:\ along with msdb because it's the most reliable drive and the worst database to lose would be the master. Tempdb will be on a separate drive increase it goes through a sudden growth spurt. There is only two drives on the systems to work with. We won't allow the C:\ drive to run out of space, nothing else will be installed on it. The server host SQL only, all data files that grow frequently will be on another drive, plus we monitor it tightly.